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Taking 802.11n Control to the Clouds

Sweet Briar College has adopted technology that allows it to save money on WiFi controllers and expand its 802.11n network across the entire campus

By Bridget McCrea

12/03/09

One of the biggest expenses with a new wireless network can be the controllers. After all, for every 50, 100, or 200 access points--the number of APs a controller can handle varies widely, depending on the network type and the vendor, among other things--you need another wireless controller. That single item might run $25,000 or more, punching a significant hole in a wireless budget.

Sweet Briar College, a small, 108-year-old women's college in Virginia with a nine-to-one student-faculty ratio, got around the controller issue completely by going with a wireless 802.11n network scheme in which the controllers are located off campus, or "in the cloud." That decision saved Sweet Briar enough money that it was able to buy half again as many APs as it had originally planned, and to jump from an 802.11g network to state-of-the-art 802.11n.

Prior to the Meraki installation over the last summer, Sweet Briar had an older wired campus-wide network, which it also upgraded to a wired system from Juniper Networks. In terms of wireless, the college had only scattered patches of wireless access, many created by students as needed and none connected to each other. This often created wireless chaos, explained Aaron Mahler, Sweet Briar's director of network services, with small wireless fiefdoms all over campus, each a stand-alone network sporting a different name. "It got to be a real headache from a user point of view," Mahler said.

To bring a much-needed campus-wide wireless network to the 1,000-student college, Sweet Briar worked with Meraki Networks, which offers a wireless solution that takes advantage of advances in communication technology and security to create a network in which the vendor supplies and manages the wireless network controllers offsite.

Not having to physically deal with controllers can make issues such as adding additional access points much easier, especially if those APs would have triggered purchase of a new controller to manage them. With Meraki, Mahler said, adding an access point involves simply connecting it to the network and synching it up with the controller it will report to, as with any AP--except that the controller is remotely located. This eliminates the need to calculate whether and when a new controller is needed--and to find room in the budget to pay for one.

With the Meraki system, all controllers and servers for the wireless network are hosted at Meraki as Web-based Cloud Controllers. Network administrators at Sweet Briar can access, control, manage, and optimize the network from a Web browser from anywhere. Having the system off-site "doesn't affect our control in any way," Mahler explained. And since no data resides on Meraki's systems, "it's not a hosted system in any sense," he said.

Another advantage with an offsite controller system is that it avoids the need for wired connections between controllers altogether. Like most older campuses, Sweet Briar also has a mix of older and newer buildings across its 3,250 acres, making it challenging to run wires through old buildings. The wireless network covers the campus indoors and out, including academic areas, residential halls, common areas, and Sweet Briar's hotel and conference center.

Mahler said that although he wasn't necessarily a big proponent of the cloud computing concept going into the project, Meraki's design "grabbed me immediately.... It just really fit what we wanted to do. The radios are completely stand-alone units. We register them [with Meraki] and receive configuration. They get an IP address from our campus, and they can converse." No actual data moves to and from Meraki, he explained; each AP is simply an autonomous device on the network. Installation of a new AP, Mahler said, can be a 10-minute process.

Because the Meraki network pricing doesn't include controllers or servers, Sweet Briar ended up jumping from its original plans for an 802.11g network to a faster and more state-of-the-art 802.11n. "All the other vendors we looked at [required] the old radio-and-controller combination," Mahler said, "which affects the price tremendously." By eliminating purchase of controllers, "we got to take a big leap forward."

Sweet Briar hasn't experienced any interruptions in service, Mahler said, nor has performance been impacted by offsite controllers and servers. Authentication of each device that joins the wireless network is handled locally in the Meraki scheme, so even if outside connections to the network are down and there is no communication beyond the campus, the access points and wireless user devices across campus can continue to communicate with each other.

Sweet Briar is using Meraki MR11 and MR14 access points, both of which include a feature called mesh networking that enables an access point to repeat the signal of another access point, eliminating the need for Ethernet cabling to APs as long as power is available and the AP is within range of another radio. The MR14, Mahler explained, is dual-band, offering both 802.11a/b/g and 802.11n capabilities, which can mean better performance when users with both 802.11a/b/g and 802.11n devices are accessing the same AP. That's because an access point from any vendor typically "steps down" in speed to accommodate the slower device when both 802.11a/b/g and 802.11n devices are in use.

The MR11s and MR14s draw power over their Ethernet cables using industry-standard PoE. "In our situation," Mahler explained, "we have enough switches and PoE ports in our Juniper [wired network units] to run every MR11 or MR14 back to a closet." That means that power is provided by the Juniper wired switches without the need for separate power-over-Ethernet injectors, which are also available from Meraki for situations where Ethernet connections back to the wired network aren't feasible as a power source.

Since the switches are the power sources as well as the data sources, Mahler explained, each Meraki AP is a self-sufficient, non-meshed node. The units keep track of one another, so that should the network path through the Ethernet to any of the units fail but maintain power, the AP will switch into meshing mode, using its WiFi path to a nearby AP until the network is restored. "This adds something of a self-healing nature to our WiFi network," Mahler said.

Regarding pricing, Sweet Briar chose Meraki's Enterprise deployment plan, which is based on a yearly per-AP cost. Mahler recommended the Enterprise route for campuses, "since it gives us greater control over the behavior of the network, namely operating the APs as bridges so that our DHCP server issues IPs to our clients rather than them being proxied by the AP itself."

So far, Mahler said, he's extremely pleased with the wireless network. "We accomplished far more than we had hoped to achieve" initially, he said. The college is now just 20 radios away from full wireless coverage across campus, including throughout a new gym under construction. Meanwhile, he said, "Having a good working network infrastructure is critically important. We can't have an experience where student comes from home [used to] a good broadband and has a lesser experience here."